Authoring system and method

ABSTRACT

A DVD authoring system in a processor-based system removes an author from consideration of the DVD Specification during authoring. According to a preferred embodiment, the authoring system provides an authoring engine having an interactive graphical authoring interface, a data management engine, an emulator, a compiler, a multiplexer and a simulator. Using summary authoring data, the compiler builds a skeleton-form PGC layout structure comprising control PGC abstractions and router PGC abstractions. The compiler then resolves the PGC abstractions according to source-target connections. During playback on a DVD player, the PGC abstractions form elements in a connection-switching abstraction superstructure. Accordingly, in response to DVD-consumer and other control events, a source PGC preferably determines target PGC information and then transfers control, via virtual connections through necessary router PGC abstractions, to a target PGC abstraction. The target PGC abstraction then correspondingly initiates playback of a movie chapter or displays a menu.

FIELD OF THE INVENTION

[0001] The present invention relates generally to mass data storage andretrieval, and more particularly to apparatus and methods for authoringa digital versatile disk.

BACKGROUND OF THE INVENTION

[0002] New mass data storage means provide not only for storing greateramounts of multimedia and other information, but also for moreinteractive data retrieval by consumers. For example, one such storagemeans is espoused by the “DVD Specification for Read-Only Disc,Physical, File Format and Video Specifications” (DVD Consortium 1997),hereinafter referred to as the “DVD Specification”. Other examplesinclude further DVD-related technologies (e.g. DVD-Audio, DVD-RAM, etc.)as well as non-DVD technologies.

[0003] The Physical and File System portions of the DVD Specificationdefines the physical encoding and organization of data for storage onread-only digital versatile disk (“DVD ROM”) media. The Video portion ofthe DVD Specification defines a data set (“DVD-Video data set”) withwhich pre-recorded DVD-Video discs must conform in order to assureproper reading, decoding and playback when inserted into a mediareader/decoder (“DVD-player”). More specifically, the Video portionspecifies how “control data” and audio/video “presentation data” areencoded and ordered within the data set. The control data determines howpresentation of audio/video data will proceed when the disc is playedback on a DVD-player and consists of low-level state information, datastructures and instruction sets which govern what kinds of functions anduser operations a DVD player can perform.

[0004] The DVD Specification is further hereby fully incorporated hereinby reference as if repeated verbatim immediately hereinafter.

[0005] The process of encoding and authoring a DVD movie title, ascurrently practiced, includes a number of separate and distinct stepsrequiring similarly separate and distinct expertise. After movieproduction, raw film and/or video footage is edited, the soundtrack isedited and mixed, and a movie film or video master is created. Thismaster is subsequently digitized, encoded as video and audio streams andstored as data files. In accordance with the DVD Specification, theMoving Pictures Expert Group (“MPEG-1 or MPEG-2”) format is used toencode the video streams and any one or more of a number of specifiedformats (e.g. MPEG-1 or MPEG-2 Audio, Dolby AC-3, PCM) is used to encodethe audio streams. Graphic data (i.e. still or moving images forcreating menus and other presentation data) is also created and storedin conventional graphic files. Finally, authoring guidelines, theencoded audio and video stream files and the graphic files are gatheredfor the authoring phase.

[0006] During authoring, a DVD author utilizes the guidelines and fileinformation to construct a DVD movie-title. The authored movie-titledetermines what a user of a resultant movie title will see and hear, andwhat kinds of interactions the user can command when the movie title isplayed back by a DVD-player. The author organizes the video, audio and(often author-created) subtitle files, divides the movie into segments(“chapters”), creates menus, and specifies low-level instructions. Thelow-level instructions will set parameters, define fixed or optionaljump points and their destinations and determine the order and optionsby which playback of still pictures, movie chapters and associated audiotracks will proceed based on the user's menu selections and/or use ofother DVD-player controls (i.e. typically using a remote controldevice).

[0007] Once authored, the author's organizational decisions, subtitle,chapter and menu decisions, and low-level instructions are compiled intocontrol data, and the encoded video, audio and subtitle streams, as wellas the graphic data files, are multiplexed into presentation data, whichtogether constitute the DVD-Video data set. Finally, this DVD-Video datais converted into a “disc image layout” file, which can be used to burna “write-once DVD-R” disc, or can be stored onto a tape to send to aDVD-ROM manufacturing plant for creating a “master” disc, which can thenbe used for replication.

[0008] Conventional DVD authoring systems comprise a computer systemrunning an application-specific DVD authoring program. An exemplary,widely used conventional DVD authoring system is Scenarist-II.

[0009] Scenarist-II is essentially an attempted, nearly directembodiment of the DVD Specification. Using Scenarist-II, an authororganizes data streams, and constructs menus and DVD structuresaccording to the DVD Specification. Top level structures (i.e. up to 99“VTSs” and “VTSMs”, a “VMG” and a VMGM”) are constructed by selectingthe structure type and then populating the structure with one or morelow-level command segments (“program chains” or “PGCs”) including movieor menu references. Throughout this process, the author also selectsfrom among available data formats, as well as from among the numerousDVD options and requisite parameters, using a number of provided listsand other data and parameter representations. Stated alternatively, allstructures and PGC parameters, capabilities and references must be fullyspecified by the author on an ongoing basis during authoring.

[0010] Unfortunately, the DVD Specification is very complex, as are theconventional programs that attempt to embody it. Available options areextensive, as are the numerous listings of options and parameters withinprograms such as Scenarist-II. The potential combinations of structuresand PGCs are also extensive, and many such combinations will notultimately result in functional DVD movie-titles.

[0011] To make matters more difficult, the PGCs (i.e. basic and frequentconstructs of the DVD Specification and therefore of programs such asScenarist-II) are counter-intuitive. Often, many PGCs (including bothoperative and so-called “dummy” PGCs) must be used in specificcombinations to provide a DVD consumer with even the most basic controlcapabilities. Limitations imposed by the DVD Specification must also beconsidered throughout the process. Thus, errors in planning and/orprogramming might well remain undetected until after a substantialnumber of structures are formed. In addition, given the sheer number ofstructures, PGCs, commands, options and parameters involved,identifying, locating and correcting errors is difficult andtime-consuming.

[0012] Consequently, while providing extensive low-level control and anexpedient authoring-to-compilation correspondence, conventionalauthoring systems require an extensive expertise with regard to both theDVD Specification and the authoring system itself. Further, evenassuming such expertise, authoring is extremely time-consuming and istherefore typically very costly. In addition, even assuming resolutionof other factors, the time and expertise required would likely preventauthoring of even a preliminary movie-title as a directorial aid duringthe movie production process.

[0013] A further disadvantage of conventional authoring systems is thatexperimentation and all but necessary modification are often compromiseddue to time and cost considerations. Thus, many DVD movie titles (due tolimited budget to support expensive authoring time) provide a DVDconsumer with only minimal playback control, navigation flexibility andinteractivity.

[0014] Accordingly, there is a need for an authoring system and methodthat enables DVD authoring in a manner removed from the structures andlow-level instruction sets of the DVD Specification, thereby reducingthe time, cost and complexity of the authoring process.

[0015] There is further a need for such an apparatus and method wherebyauthoring can be conducted in an intuitive manner, while maximizingflexibility and access to features provided by or otherwise not inconflict with the DVD Specification.

SUMMARY OF THE INVENTION

[0016] The present invention provides a data processing-system basedauthoring system and method that essentially removes an author fromconsideration of the structures and low-level instruction sets of theDVD Specification. More specifically, the present authoring systemremoves the ordered tasks associated with creating DVD structures andprogramming PGCs, and replaces them instead with an interactive,intuitive and graphical authoring environment.

[0017] The present invention further provides for flexible program flowin response to control events. Many interactive controls, menu buttondestinations and other features that are possible in accordance with theDVD Specification can be specified by an author in multiple instancesand according to quick, intuitive and interactively modifiableselections. Thus the invention facilitates authoring of a DVD movietitle by even an inexperienced author with context sensitiveresponsiveness to DVD consumer instructions and other DVDplayer-generated events.

[0018] Accordingly, a preferred embodiment of the present inventioncomprises an authoring engine having an integrated interface with whichan author performs the above tasks a data management engine for storingand recalling authoring information, a simulator for viewing progressiveand/or comparatively authored movie titles prior to compiling, acompiler, a multiplexer and an emulator for viewing authored movietitles after compiling and multiplexing.

[0019] Included within and facilitating the ability of these elements toremove an author from the DVD Specification are several abstractions.Preferably, the interface provides such “user abstractions” as arrangingmovies (i.e. data streams including video, audio, subtitles, chapterpoints and other elements), creating menu layouts (i.e. menus, menubuttons and still or moving images with or without sound) and specifyingconnections among these arrangements and layouts, each in a simple andintuitive, yet highly flexible way. Further abstractions include anetwork or connection-switching abstraction and a number of control androuter PGC abstractions from which the connection-switching abstractionis constructed.

[0020] Authoring instructions entered through the interface arepreferably broken down into component parts and stored by the datamanagement engine. The invoked compiler, using only summary authoringinformation, preferably constructs a skeleton form PGC layout structurecomprised of PGC abstractions corresponding to the number of authoredmovie elements. The compiler then completes the layout structureaccording to author-selected and default source-target connections.

[0021] Further according to a preferred embodiment, during playback of aresultant DVD movie title, a source PGC abstraction is invoked inresponse to DVD player and/or consumer instructions. The source PGCabstraction determines target information and transfers control, throughnecessary router PGC abstractions, to a target PGC abstraction. Thetarget, in accordance with the target information, plays a moviechapter, displays a menu, or sets and/or modifies one or more DVDparameter.

[0022] These and other objects, advantages and benefits of the presentinvention will become apparent from the drawings and specification thatfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is functional block diagram generally illustrating anauthoring system according to a preferred embodiment of the invention;

[0024]FIG. 2 is a functional block diagram illustrating in more detail apreferred authoring program of the authoring system shown in FIG. 1,according to the invention;

[0025]FIG. 3 is a screenshot of a preferred performance elementarrangement interface portion of the FIG. 2 authoring program, accordingto the invention;

[0026]FIG. 4 is a blowup of the FIG. 3 screenshot showing, in moredetail, a preferred authoring toolbar for accessing authoring programmodules and functions;

[0027]FIG. 5 is a flowchart illustrating an exemplary method used by anauthor to create a performance element arrangement using the performanceelement arrangement interface portion of FIG. 3;

[0028]FIG. 6a is a flowchart illustrating preferred responses of theauthoring program to authoring while the performance element arrangementinterface portion of FIG. 3 is active;

[0029]FIG. 6b is a flowchart further illustrating preferred responses ofthe authoring engine to authoring while the performance elementarrangement interface portion of FIG. 3 is active;

[0030]FIG. 7 is a screenshot of a menu element layout interface portionof the FIG. 2 authoring program, according to the invention;

[0031]FIG. 8 is a flowchart illustrating an exemplary method used by anauthor to create a menu layout using the menu element layout interfaceportion of FIG. 7;

[0032]FIG. 9 is a screenshot of a preferred connections interfaceportion of the FIG. 2 authoring program, according to the invention;

[0033]FIG. 10 is a screenshot of a preferred simulator interface portionof the FIG. 2 authoring program, according to the invention;

[0034]FIG. 11 is a functional block diagram of a preferred datamanagement engine according to the invention;

[0035]FIG. 12a is a flowchart showing generally the operation of apreferred compiler according to the invention;

[0036]FIG. 12b is a flowchart showing how a compiler according to theinvention preferably constructs a skeleton-form PGC layout structure;

[0037]FIG. 12c is a flowchart showing how the compiler preferablyresolves source-target connections and substitutes those connections fornull operations in a preferred skeleton-form PGC layout structure,according to the invention;

[0038]FIG. 13 is a block diagram showing the format of a preferred PGClayout structure according to the invention;

[0039]FIG. 14 is a functional block diagram showing a preferredconnection-switching abstraction according to the invention;

[0040]FIG. 15 is a flowchart showing a preferred operation of theconnection-switching abstraction of FIG. 14, according to the invention;

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

[0041] For clarity sake, the discussed embodiment herein will bedirected primarily toward storage according to the DVD Specification,and more specifically at authoring motion picture DVD ROMS (“movietitles”). It should be understood, however, that the present inventionrelates to a broad range of program and data storage and retrievalutilizing a variety of media, only a subset of which will bespecifically identified herein. The types of DVD ROMS which can beauthored are further in no way limited to movie titles. Other examplesinclude but are not limited to music videos, documentaries, educationalvideos, corporate training, medical applications and other continuousplay or interactive information which utilizes audio, video and/or otherpresentation data.

[0042] As illustrated in FIG. 1, a preferred embodiment of authoringsystem 100 according to the invention preferably comprises electricallyconnected hardware elements including input devices 110, processor 115,memory 120, storage 125, MPEG encoder/decoder 130, video I/O device 135and audio I/O device 140. Authoring system 100 further comprisessoftware elements including operating system 150, authoring engine 160,data management engine 165, compiler 170, simulator 175, emulator 180and multiplexer 185.

[0043] It will be apparent to those skilled in the art that severalvariations of the authoring system elements are contemplated and withinthe intended scope of the present invention. For example, givenprocessor and computer performance variations and ongoing technologicaladvancements, hardware elements such as MPEG encoder/decoder 130 may beembodied in software or in a combination of hardware and software.Similarly, software elements such as multiplexer 185 may be embodied inhardware or in a combination of hardware and software. Further, whileconnection to other computing devices is indicated as network I/O 145,wired, wireless, modem and/or other connection or connections to othercomputing devices (including but not limited to local area networks,wide area networks and the internet) might be utilized. A furtherexample is that the use of distributed processing, multiple siteviewing, information forwarding, collaboration, remote informationretrieval and merging, and related capabilities are each contemplated.Various operating systems and data processing systems can also beutilized, however at least a conventional multitasking operating systemsuch as Windows95® or Windows NT® (trademarks of Microsoft, Inc.)running on an IBM® (trademark to International Business Machines)compatible computer is preferred and will be presumed for the discussionherein. Input devices 110 can comprise any number of devices and/ordevice types for inputting commands and/or data, including but notlimited to a keyboard, mouse, and/or speech recognition. (The use of akeyboard and a mouse are exemplified throughout the discussion thatfollows.)

[0044] The FIG. 2 block diagram illustrates in greater functional detailan authoring program 201 of the preferred authoring system of FIG. 1. Asshown, authoring program 201 comprises authoring engine 160 (whichincludes interface 160 a), data management engine 165, compiler 170,simulator 175, emulator 180, multiplexer 185, output DVD data storage290 and layout formatter 187, user abstractions 285 and PGC abstractions287.

[0045] It is discovered through examination of the features supported byDVD players that the basic presentation data types and consumer controlsavailable to an author of DVD movie titles can be generalized and thenreconstructed as abstracted user data types and controls. Further,despite the complexity of the DVD Specification, many of its programmingconstructs can also be generalized and then reconstructed as abstractedDVD program chains (“PGCs”) operating within a further abstractednetwork or connection-switching superstructure. Such user abstractions285 and PGC abstractions 287, as integrated into authoring engine 160,data management engine 165 and compiler 170 (as illustrated),effectively remove an author using authoring program 201 fromconsideration of DVD Specification 205. These abstractions furtherremove such consideration without unduly limiting, for most practicalpurposes, authoring flexibility, PGC efficiency or interactiveresponsiveness of a resultant DVD-ROM, among other factors. In addition,these abstractions provide a framework of re-useable components that arereadily adaptable to further modification for providing improvements,and for re-use in a variety other DVD and non-DVD applications.

[0046] Authoring program 201 is preferably implemented in C++, anobject-oriented language, for reliability, updateability and other knowngeneralized advantages of object-oriented programming. Those skilled inthe computer arts will appreciate however, that despite such advantages,other environments and/or programming languages of variousobject-oriented and non-object-oriented types can also be utilized.

[0047] Operationally, an author enters authoring information andinstructions for activating and controlling authoring program 201through interface portion 160 a of authoring engine 160. Authoringengine 160 interactively receives entered information and commands bycorrespondingly adjusting interface portion 160 a, invoking a furtherauthoring program module, sending entered authoring information to datamanagement engine 165, retrieving authored information from datamanagement engine 165, and sending and/or retrieving presentation datafrom presentation data storage 203. Data management engine 165 respondsto authoring engine 160 by receiving and storing authored informationfrom authoring engine 160 and/or sending information, which it retrievesfrom storage (and/or from a remote source), to authoring engine 160.Simulator 175 responds to authoring engine 160 by retrieving authoringdata from data management engine 165, retrieving multiplexedpresentation data from multiplexer, and simulating an authored DVD-ROMin conjunction with interface 160 a.

[0048] Compiler 170 responds to authoring engine 160 by retrievingauthored information from data management engine 165, compiling theinformation and storing the compiled information (“.ifo files”) inoutput DVD data storage 290. Emulator 180 responds to authoring engine160 by retrieving compiled data from output DVD data storage 290,retrieving multiplexed data from output DVD data storage 290 andemulating an authored DVD-ROM in conjunction with interface 160 a.Multiplexer 185 responds to authoring engine 160 by receiving DVDparameter information from compiler 170, retrieving presentation datafrom presentation data storage 203 and combining the retrievedinformation and data in accordance DVD Specification 205. Multiplexer185 then stores the combined information and data (“DVD data stream” or“.vob file”) in output DVD data storage 290. Layout formatter 187retrieves the .vob files and .ifo files from output DVD data storage 290and combines these files into a single “disc image” file, which it thenstores in disc image file storage 207. The disc image file can then besent through network I/O 145 (FIG. 1) to additional apparatus forfurther review, processing and/or for burning one or more DVD-ROMs 207.

[0049]FIGS. 3 through 10, with reference to FIG. 2, illustrate how aninterface according to the invention enables an author to assemble amovie title essentially removed from DVD programming specifications 207(FIG. 2) of the DVD Specification. Preferred interface 160 a isillustrated as an application running under a Windows95® or Windows NT®(trademark of Microsoft, Corp.) operating system.

[0050] The FIG. 3 screenshot illustrates a preferred authoring window300, which an author can utilize to select an arrangement ofaudio-visual material including video segments (“video clips”), audiosegments (“audio clips”) and subtitles (hereinafter referred tocollectively as “performance data”).

[0051] Authoring window 300 is divided into movable, modifiable andreplaceable groupings or “views” and “panels” including presentationdata panel 301, performance assembly panel 302, assembled elements panel307, log panel 308 and preview video panel 309. Assembly panel 302 isfurther divided into video assembly portion 320, audio assembly portion330 and subtitle assembly portion 340 (which are collectively referredto herein as performance view 303), and performance tools portion 360.Authoring window 300 also includes authoring toolbar 399 a and menu bar399 b. For clarity sake, the following discussion assumes that a single,continuous movie is being authored (i.e. a movie having component video,audio and subtitle data streams each of which begins at the start of themovie and ends at the conclusion of the movie).

[0052] Presentation data panel 301 provides a display listing for eachpresentation data file that an author has selected and loaded for use inassembling movies and menus either during a current authoring session orwhen continuing a re-initiated, prior authoring session. File listingsinclude file name 311, file duration 313, and file type 315 parameters.File name 311 lists the name of a file. File duration 313 lists theplayback duration of files such as video data files and audio datafiles. File type 315 alternatively lists a file format, which isgenerally indicated by a filename extension, or a recognized data typesuch as “video” data or “audio” data. As will be further discussed,presentation data file listings can be used interactively during anauthoring session.

[0053] Performance assembly view 303 of performance assembly panel 302is used by an author to graphically and interactively assemble loadedvideo and/or audio data, to add and assemble subtitles, and/or to addchapter points. For these purposes, performance view 303 includes videoassembly portion 320, audio assembly portion 330, subtitle assemblyportion 340 and chapter assembly portion 350 respectively. Videoassembly portion 320 is used by an author to assemble graphic objectsreferencing stored video data files (“video clips”). As discussed, thesefiles, once initially selected, are listed in presentation data panel301. Video frame thumbnails 323 a and 323 b are indicative of chapterpoints as will be further discussed herein.

[0054] Audio assembly portion 330 of performance assembly panel 302 isused by an author to receive graphic objects referencing stored audiodata files (“audio clips”). As with video clips, audio clips, onceselected for use, are listed in and selected from presentation datapanel 301 for arrangement purposes. Up to eight (alternate language)audio data streams or audio “tracks”, exemplified by audio tracks 331 athrough 331 c, are available in accordance with DVD Specification 205(FIG. 2). Audio bars 332 a and 332 b, which represent author-arrangedaudio clips, have a length that reflects the playback time of the audiodata represented. Separators 333 are further indicators of chapterpoints, as with video frame thumbnails 323 a and 323 b of video assemblyportion 320. Audio tracks 332 a through 332 c further include audioencoding indicators 334 a, audio format indicators 334 b, track numberindicators 335 and selected language indicators 336, which areindicative respectively of audio data file encoding and playback format,selectable audio track number 336 and modifiable language label 335.Language labels 335 can be set by author selection or, as is expected,automatically by recognition of languages spoken in a recorded dialog ofa respective audio track.

[0055] Subtitle assembly portion 340 provides for entry, retrievaland/or editing of up to thirty-two (alternate language) frame-basedsubtitle sequences, as exemplified by tracks 341 a and 341 b. Exemplarysubtitle frames 342 a and 342 b illustrate textual subtitle contents.Subtitles are entered in a conventional manner using a conventional texteditor (not shown) which is invoked by activating a subtitle frame (e.g.by menu selection or double-clicking) and/or by retrieving apre-existing subtitle file using, for example, presentation data panel301. As with audio assembly portion 330, subtitle portion 340 includesselectable track numbers and modifiable language label indicators.

[0056] Performance assembly view 303 also includes chapter assemblyportion 350, which is used by an author to graphically and interactivelyassemble chapter points. Chapter assembly portion 350 includes wallclock 351, reference offset clock 352, author-assembled chapterindicators 353 a through 353 c, chapter time indicators 354 a through354 c and reference time indicators 355 a through 355 c. Wall clock 351indicates a time within a video clip corresponding to a cursor positionover chapter portion 350 of assembly panel 302. Offset clock 352indicates the start time of a currently indicated video clip accordingto the reference timecode of a master tape (i.e. from which the videodata file was created). Chapter indicators 353 a through 353 c showchapter points (i.e. points to which a DVD-ROM consumer can advance) asarranged during authoring. Chapter time indicators 354 a through 354 cand reference time indicators 355 a through 355 c display the elapsedtime of corresponding selected chapter points from the start of a movieand from the start of a clip respectively. Reference times are typicallyrecorded (and thus can be selectively retrieved and displayed) utilizingSociety of Motion Pictures and Television (“SMPTE”) timecode.

[0057] As noted earlier, performance assembly panel 302 and the otherpanels and views of authoring window 300 are replaceable. Tabs 302 aprovide one alternative control structure for selectively switchingbetween initiated or “open” authoring tasks, for example, to alternatebetween assembling presentation data of multiple movies, for creatingmenu layouts, and/or for other authoring tasks. Other control structuresinclude menu options (not shown) for selectively de-coupling panels andtransport enabling controls (362 a through 362 c and 363 a through 363b), and further for re-coupling in the illustrated default arrangement,in an author-selectable arrangement and/or interactively by an author.Panels can be resized and/or re-arranged among other windowcapabilities, as will be understood by those skilled in the art in viewof the discussion herein.

[0058] Assembly tools portion 360 of performance assembly panel 302comprises selectable zoom controls 361 a through 361 c, previewtransport buttons including stop 362 a, play 362 b and frame advance 362c, preview transport start time selector 363 a and stop time selector363 b, selected clip indicator 364 a and total clips indicator 364 b.Zoom controls 361 a through 361 c are used respectively for increasingthe viewable data range of a selected area within performance assemblyview 303 of performance assembly panel 302, for selecting a portion ofperformance assembly view 302 for such viewing, and for decreasing theviewable data range. Transport controls 362 a through 362 c providevideo playback control when previewing a video clip, audio clip and/orsubtitle data using preview video panel 309, or when selecting arepresentative video frame in a video clip as a preview thumbnail (aswith exemplary thumbnails 323 a and 323 b). Transport control 362 ahalts video, audio and/or subtitle playback, transport control 362 binitiates/continues playback and transport control 362 c provides forper-frame (“step”) viewing, as will be understood by those skilled inthe art. Start and end time selectors 363 a and 363 b are usedrespectively for selecting and monitoring video, audio and/or subtitleplayback position and for setting and monitoring a playback stop time.

[0059] Assembled elements panel 306 provides interactive and selectablelistings of authored contents of a current movie title, including butnot limited to movie volume 361, movies 362 and menus 363.

[0060] Log panel 308 provides selectable progress reports and otherinformation relating to decoding/encoding of presentation data,compiling and layout of a disk file format according to DVD disk formatspecifications 205 (FIG. 2). These reports are automatically created andcan be accessed using log tabs exemplified by tabs 381 and 383.

[0061] Preview video panel 303 selectively displays a video framecorresponding to a cursor position over assembly panel chapter portion350, video assembly portion 320, audio assembly portion 330, subtitleportion 340 and/or chapter portion 350 of assembly panel 302. Inaddition, preview video panel is used for previewing video data usingtransport controls 362 a through 362 c, start and stop time selectors363 a and 363 b or directly invoking the panel using selection ordrag-and-drop capabilities. (As will be understood by those skilled inthe art, encoded video and audio files are decoded and buffered, asneeded, for playback in a conventional manner using MPEG encoder/decoder130 of FIG. 1.)

[0062] The following toolbar chart lists the respective elements oftoolbar 399. It will be understood by those skilled in the art, in viewof the discussion herein, that the toolbar elements can varysubstantially and includes user-defined expandable and replaceableelements. The elements shown are provided as defaults. Label Referencedas Description 401 New volume Loads default values and adjusts theinterface for a new movie title. 403 New menu Loads default values andadjusts the interface for a new menu layout. 405 New movie Loads defaultvalues and adjusts the interface for authoring a new movie. 407Connections Switches to an existing connections interface or adjusts theinterface, according to default values for initially settingconnections. 413-415 Cut, copy and paste Provide conventional functionsexcept as described herein for connections. 421 Compile start Initiatingcompiler operation. 423 Compiler stop Interrupts compiler operation. 425DVD Layout Invokes DVD Disk layout operation. 427 Write Tape Providesfor output of multiplexed data stream to tape. 429 Simulator Invokessimulator

[0063] The FIG. 5 flowchart illustrates, by way of example and withreference to FIGS. 3 and 4, how an interface in accordance with theinvention enables an author to assemble performance data and objectswithout consideration for structures, commands or ordered tasks imposedby DVD programming specifications 207 (FIG. 2). Select, open anddrag-and-drop, among other operations, and clicking, double-clicking,click-and-drag and other user actions associated with graphic interfacesare well known and will not be further expounded upon herein.

[0064] As shown, in step 505, an author initiates a new project(“volume”) by selecting new volume 401 (FIG. 4). In step 510, the authorinitiates a new movie by selecting new movie 405. In step 515, theauthor adds video and audio files to presentation data panel 301 (FIG.3) for potential use in the volume by movies and menus. In step 520, theauthor can preview a video file in preview panel 304 by dragging itsicon in presentation data panel 301 to preview panel 304 and/or, ifdesired, by invoking transport controls 362 a through 362 c, previewtimer 393 and/or other playback-related controls. In step 525, theauthor adds a selected video clip to the currently opened movie bydouble-clicking its icon in presentation data panel 301 or by draggingthe icon from presentation data panel 301 to video assembly portion 320of performance view 303. In step 530, the author can select a videoframe thumbnail other than a first frame for reference viewing bydragging the pointer of thumbnail timer 325 a and/or by using transportcontrols 362 a through 362 b.

[0065] In step 535, the author can preview an audio file by selectingits icon in presentation data panel 301 and using controls includingstop 362, play 362 b, using start time and end time selectors 363 a and363 b and/or using other play-related controls. In step 540, the authoradds a selected audio clip to a next available track of the currentlyopened movie by double-clicking its icon in presentation data panel 301.(Alternatively, the author can add a selected audio clip to a specificaudio track by dragging the icon from presentation data panel 301 to aselected track in audio assembly portion 330 of performance view 303. Instep 545, the author selects a language label by selecting selectedlanguage indicator 335 and selecting a listed element.

[0066] In step 550, the author opens a subtitle frame and enterssubtitle information for display in a video frame during playback ofvideo clips. In step 555, the author selects a language labelcorresponding to the subtitle track containing the subtitle frame. If,in step 560, the author elects to add more performance data, then theauthor returns to step 520.

[0067] In step 565, the author moves a cursor within chapter assemblyportion 350 of performance view 303 to view video frames available aschapter points. In step 570, the author selects a chapter point. If, instep 575, the author elects to add more chapter points, then the authorcontinues at step 565.

[0068] In step 580, the author selects an audio track number andoptionally selects a subtitle track number and/or playback start and/orend times before selecting play button 362 b to preview playback of thevideo clip and the audio clip referenced by the selected track number.

[0069] The FIGS. 6a and 6 b flowchart (with reference to FIGS. 2 and 3)generally illustrates responses by the preferred authoring program 201to an author's actions according to the invention. As shown, if in step602 an author selects a movie assembled in a prior authoring session,then, in step 604, data management engine 165 (FIG. 2) loads relatedparameters and, in step 606, sends the parameters to authoring engine160. Otherwise, default parameters for a new movie are loaded in step608.

[0070] In step 609, authoring engine 160 updates assembled elementspanel 307 (FIG. 3) and other affected interface 160 a elements toindicate the movie parameters. If, in step 612, the author selectspresentation data files, then data management engine 165 loads and sendsthe respective presentation data file parameters to authoring engine 160in step 614, which updates presentation data panel 301 in step 616. If,in step 622, the author assembles one of the selected video clips, thenauthoring engine 160 accordingly updates video assembly portion 320,chapter assembly portion 350 and offset clock 352 in step 624, updatesassembled elements panel 307 in step 626, and sends the video clipparameters to data management engine 165 for storage in step 628.Similarly, if the author assembles one of the selected audio clips instep 632, then authoring engine 160 updates the selected track of audioassembly portion 320 in step 634, updates assembled elements panel 307in step 636, and sends the audio clip parameters to data managementengine 165 in step 638. If, in step 642, the author assembles subtitledata, then authoring engine 165 updates subtitle assembly portion 340 instep 644, updates assembled elements 307 in step 646, and sends subtitledata and parameters to data management engine 160 in step 628.

[0071] If, in step 652, the author moves an interface 160 a pointer(e.g. a mouse pointer) within chapter assembly portion 360, then in step654 authoring engine 160 updates wallclock 351, finds an I-frame (i.e. avideo frame that is completely described without reference to otherframes) within the video clip corresponding to the mouse pointerposition and displays the I-frame in preview video panel 309. If, instep 672, the author assembles a chapter point, then authoring engine160 updates video assembly portion 340 and chapter assembly portion 350in step 674, updates assembled elements panel 307 in step 676, and sendscorresponding chapter parameters to data management engine 165 in step678.

[0072] The FIG. 7 screenshot illustrates the preferred authoring window300 of FIG. 3 with the performance data assembly panels replaced bypanels for allowing an author to layout menus. More particularly, menulayout panel 701 and menu tools panel 702 ate selected, sized andpositioned to replace performance view 303 of FIG. 3. An exemplary menulayout including graphic and textural images is shown in menu layoutpanel 701 for purposes of illustration. Menu layout panel 701 is usedvisually and interactively by an author to retrieve, add, place andmodify menu elements using menu tools panel 702 selections.

[0073] In accordance with the DVD Specification, menu elementspresentable to a DVD consumer can include a background image(“background”), an overlay image (“subpicture”) and up to twenty-fivebuttons. For the present example, author-selected background 710 is amulticolor design, and author-selected subpicture 711 includes thetextural information, Dolby Demo 1, Dolby Demo 2, Play Both Demos andMain Menu. Four author-created buttons 720 a through 720 d includingbutton frames 721 a through 721 d are also shown. Each of button numbers722 a through 722 d is added by authoring program 201 (FIG. 2) inresponse to creation of a respective button for identification purposes(i.e. during authoring and for use in compilation).

[0074] Menu tools panel 702 comprises controls for implementingselectable menu element parameters and for selectably altering thedisplay characteristics of elements within menu layout panel 701 duringan authoring session. For example, color selection boxes 732, 734, 736and 738 allow an author to choose a button outline color for display (ina consumer viewing scenario) when a button is not selected (“normal”),when a consumer points at the button (“selection”) and when a button isinvoked (“action”) respectively. An author can also select the opacityof the buttons for these cases using opacity sliders 733, 735, and 737respectively. Similarly, an author can select button shapes and othercharacteristics by selecting one of the layout feature tabs 739 andutilizing the tool sets that appear in a respective tool set panel (notshown). An author might, for example, utilize prior button shape, color,texture, opacity and/or normal, selection and activation colorcombinations used with a prior authoring session as either a startingpoint for further changes or without further modification. Otherparameter combinations might also be utilized. Safe area toggle 755 aallows an author to selectively display safe area indicator 755 b ofmenu layout panel 701 (which bounds an area that is assured to bedisplayed on a consumer television). Display controls 751 and 752provide for altering the characteristics indicated which, in light ofthe prior discussion, will be understood by those skilled in the artwithout further edification.

[0075] Layout feature tabs 749 also provide access to button orderingtools (not shown). As with other authoring parameters, an author canselectively utilize an existing order of buttons that will be traversedin a currently displayed menu when a consumer pushes directional buttonson a remote control device. An alternative order can also be set usingany number of methods including but not limited to using a displayedremote control device or dragging an arrow from a starting point to anending point. Such features and their operational characteristics, giventhe foregoing, will be understood by those skilled in the art withoutfurther edification.

[0076] The FIG. 8 flowchart shows how the actions required for layingout a menu are consistent with those for assembling performance data.Once again, authoring is visually and interactively achieved withoutrequiring any specific ordering of actions. Therefore, as withperformance data assembly, the specific ordering of actions is given forpurposes of illustration only.

[0077] As shown, in step 805, the author selects background andsubpicture files for inclusion in a menu layout. Selected files willappear in presentation data panel 301 (FIG. 7). In step 810, an authoradds a background and a subpicture to the current menu bydouble-clicking on file listings, dragging the files to menu layoutpanel 701 or by using a similar method. In step 815, the author draws(i.e. drags a box) around subpicture text forming a button frame,thereby indicating button placement directly in menu layout panel 701.If, in step 820, more button frames remain to be added, then the authorreturns to step 815.

[0078] In step 825, the author selects a button and sets shape, size,opacity and other parameters using preset combinations and/or colorselection boxes 732, 734, 736 and 738, opacity sliders 733, 735, and 737and/or other tools. In step 830, the author sets the intra-menu buttonorder in the manner already described. If, in step 840, more menusremain to be created, then the author selects add menu button 413 instep 840, and returns to step 805. New elements appear in assembledelements panel 307 and control data (i.e. relating to added elements andtheir layout characteristics) are sent to data management engine 165(FIG. 2) as with performance data assembly.

[0079] The FIG. 9 screenshot illustrates a further selectableconfiguration of the FIG. 3 interface for linking together presentationdata, menu layouts, buttons within menu layouts and available controlfunctions of a DVD player. As shown, connection view 901 includesavailable targets panel 903 and linking panel 905. Linking panel 905further includes available sources portion 950 and connected targetsportion 960. While connections view 901 is active, assembled elementspanel 307 can further be used as a selection means for navigating morequickly to a desired target within available targets panel 903.

[0080] Operationally, an author forms a link or “available connection”simply by copying (i.e. performing a copy action or dragging) a targetfrom available targets portion 903 to a position in connected targetsportion 960 that is in the same row as a desired source in availablesources view 950. As with assembling a movie and menu layouts, an authorcan interactively remove, move or otherwise modify links in aconventional manner. For example, a link can be removed by deletion or atarget can be moved or copied to another row in linking portion 905.

[0081] As with arranging performance data and forming menu layouts, anauthor has easy and complete flexibility in adding interactivity to aconsumer's viewing experience. A DVD movie can be authored, for example,such that entry and exit from a menu can be controlled by any availableevent. Referring also to the FIG. 10 simulator window 1000, any menubutton can further be linked to any DVD event, including but not limitedto a chapter point (e.g. chapter point 953), the end of chapter playbackor depressing a DVD remote control device menu button 1020 and 1040(FIG. 10). A particular menu button can also be used as a target inmultiple instances, as might be creatively appropriate.

[0082] Thus, for example, a consumer interface can be quickly and easilycreated which is interactively responsive (“context sensitive”) to aconsumer's actions. Stated alternatively, an interface can be authoredsuch that, for example. the conclusion of a specific chapter playback ormenu button activation will determine a next chapter playback, a nextmenu or even a next menu wherein an author-selected menu button ishighlighted.

[0083] Among the reasons for such ease and flexibility is that, contraryto conventionally authored DVD movies, program chains are not createdduring the authoring process. Similarly, connections specified duringauthoring are not permanent (“hard wired”). Rather, program chains arenot created until compilation and available connections are not fullyresolved until playback, each according to additional abstractions ofthe invention, as will be further discussed herein.

[0084] The FIG. 11 block diagram illustrates the structure of apreferred data management engine 165 (FIG. 1) according to theinvention. As illustrated, data management engine 165 only partiallyreflects the interface constructs and the structures of the DVDSpecification. While reflecting interface abstractions (e.g. a movie,menu and connection based movie-title description) and DVD Specificationrequirements (e.g. first play jump source), data management engine 165is further structured as a flexible network of data storage anddistribution objects that also reflects other abstractions of theinvention.

[0085] One further abstraction, for example, is a model of a DVD player,a consumer's controller and the compiled authoring instructions as anactively connection-switched network. Within this network, DVD programchains representative of action-oriented authoring instructions(“routers”), perform switching among available connections in responseto DVD-player (i.e. consumer) instructions, thereby re-directing programflow and control. Control-receiving program chains then perform morelocalized tasks (e.g. such as displaying a menu). Stated alternatively,a router program chain resolves an available connection from aDVD-player control instruction to a receiving program chain, which againroutes control or executes the instruction. Further abstractions alsoinclude models of program chains for performing a common basefunctionality in a same or similar manner using a derived common programchain structure.

[0086] Such an arrangement provides real world flexibility andefficiency. For example, data management engine 165 supports authoringflexibility with regard to source-target connections that areswitchable. Further, given the power of even conventional computersystems, data management engine 165 is sufficiently robust to enable theinteractive operation of interface 160 a (FIG. 2) as well as minimalcompilation times of compiler 170 (i.e. only milliseconds) withoutdirect interface or DVD program specification 205 correlation. Datamanagement engine 165 is therefore also readily adaptable to interfacevariations and further interfaces, as well as to compiler variations andother compilers supporting other DVD and non-DVD data storage and/orretrieval applications.

[0087] Referring again to FIG. 11 and with further reference to FIG. 2,data management engine 165 comprises a root volume object 1100, whichmanages data management engine 165 communication and storage. Volumeobject 1100 provides an interface for communicating messaged data to andfrom its component parts, including title key jump source 1101, firstplay jump source 1102, media database 1103, DVD layout properties 1104,movies list 1105, menus list 1106 and connections list 1107 (objects).Media database 1103 further includes media files list 1130, which storespointers to media files referred to by the performance data arrangementas a result of authoring.

[0088] In addition, each of the presentation data objects (i.e. movieslist 1105 and menus list 1106) and a connection sets list object 1107contain links to other data management engine objects in the form of anobject tree. More specifically, movies list 1105 is linked to movieobjects movie-1150 a through movie-M 1150 b, wherein M is the totalnumber of movies authored for storage on a single DVD-ROM (“movietitle”). Each movie object contains a respective track list object 1151and a respective chapter list object 1152. Each track list object 1151contains respective track objects, track-1 1153 a through track-T 1153b, wherein T is the total number of tracks authored within a respectivemovie. Track-1 through track-T further contain clip lists, which in turncontain clip objects clip-1 1154 a through clip-CL 1154 b (and whereinCL is the total number of clips in a given track within a given movie).Finally, each clip object contains a respective clip properties object,as exemplified by clip object 1155.

[0089] Menu objects are structured in a manner similar to that of movieobjects. Menus list object 1160 contains menu objects menu-1 1160 athrough menu-N, wherein N is the total number of menus authored forstorage on a given DVD-ROM. Each menu object further contains arespective button list object (e.g. object 1161), each button listobject contains a respective button objects (button-1 1162 a throughbutton-B 1162 b) and each button object is linked to a button propertiesobject (e.g. object 1163). B indicates a total number of buttons in arespective menu.

[0090] Finally, connections sets list 1107 contains respectiveconnections lists (i.e. connect-list-1 1170 a through connect-list-CL1170 b), wherein CL is the total number of connections lists authoredfor storage on a given DVD-ROM. Each connect-list is further linked torespective connections objects (i.e. connect-1 1171 a throughconnect-CN), wherein CN is the total number of connections authored tofacilitate flexible program flow and control. Each connections object(1171 a through 1171 b) represents an action-oriented switch between arespective source and a respective target (as indicated bysource-pointer variable 1172 and target-pointer variable 1173), as willbe discussed further herein.

[0091] Where applicable, each object includes an indexed object listhaving a pointer to each connected dependent object (i.e. an object“further down the tree” as illustrated), as well as a totals variable.The object list is updated to include new dependent objects as theseobjects are created (“instantiated”) to reflect, for example, an addedchapter point or menu. Dependent objects are similarly removed from theobject list according to authoring deletions. Totals variables are alsoupdated during authoring to reflect each corresponding dependent objectinstantiation and deletion. Undo and redo operations are handled in aconventional manner using authoring instructions which are furtherconventionally stored within respective objects during each authoringsession.

[0092] Using this structure, data management engine 165 breaks down orfilters control data generated during authoring into its basic componentparts for storage in a corresponding object's indexed data list. Thesebasic component parts are then retrieved by authoring engine 160, orretrieved and reconstructed into an applicable form by compiler 170, asneeded.

[0093] Operationally, data management engine 165 receives messages fromauthoring engine 160 in response to and reflecting each authormodification of a performance assembly, menu layout or connection.Volume 1100 receives the message, polls its contained-objects list for arecipient object according to the message type, and sends the message tothe matching recipient object. If the message includes a reference to atitle key source or a first play source (which is author-slectable inconnections view 901), then volume 1100 sends the message respectivelyto either title key jump source 1101 or first play jump source 1102.Upon receipt, title key jump source 1101 or first play jump source 1102will accordingly store included data, delete stored data or modifystored data.

[0094] If a received message includes a reference to a video, audio orsubtitle file, then volume 1100 sends the message to media database1103. If the message contains an instruction to add a data element, thenmedia database 1103 stores the data (which will include a pointer to amedia file) in media files list 1130. If the message contains aninstruction to delete a stored pointer, then media database 1103 deletesthe pointer. If the message contains an instruction to modify a storedpointer (e.g. if the file was moved to a new location), then mediadatabase 1103 locates and replaces the file pointer. Media database 1103further updates its totals variable to reflect additions and deletions.

[0095] If a received message type relates to the content of a moviearrangement, menu layout or connection, then volume 1103 sends themessage respectively to movies list 1105, menus list 1106 or connectionslist 1107. Each of movies list 1105, menus list 1106 and connection setslist 1107 operates similarly to objects described thus far. Each parsesthrough a received message for included control information, sends themessage respectively to a corresponding movie object, menu object orconnections list and adjusts its totals variable as needed.

[0096] A movie message, for example, will then progress down through themovie object tree, and, depending upon the message type, will befiltered, by track list 1152, track-1 1153 a and then handled a matchingclip, or will be filtered by chapter list 1152 and then handled bycorresponding chapter or by a clip properties object (i.e. asillustrated). Menu layout data will similarly progress (as illustrated)down through the menus list tree, being handled by a matching menuproperties object, and connections data will progress down theconnection sets list tree until it is handled by a connection object(with reference to its source pointer or destination pointer variables).Upon receipt, a clip properties, menu key, end key, menu properties orconnection object will handle the message and store included data,delete stored data or modify stored data in a similar manner as withmedia database object 1103.

[0097] Each respective storage object stores authoring modifications ina sequentially indexed list according to its type (i.e. each object nameis illustrated to reflect the data type the object stores). Thus, forexample, chapter points within a movie are stored from a first chapterpoint during playback to a final chapter point in the movie. (Playbackwill however, be determined by authored connections.) The listaccommodates added, inserted or deleted data interactively by expandingor contracting about the addition, insertion or deletion point.

[0098] While other data structures might be utilized, interactivelyadjusted indexed lists and limited object definitions, using even aminimally equipped computer, are sufficiently robust to accommodate anauthor's input rate, given the relatively small amount of data stored ineach list. Alternative structures that might be used, for example,include but are not limited to a lesser number of objects eachcontaining a less restricted dataset and/or the addition of summaryobjects for storing total numbers of menus, buttons and system otherstatus and/or statistical information. Such arrangements however, havebeen found to add complexity with only moderate gains inapplication-specific operational characteristics. Alternative datastructures, including but not limited to multi-dimensional arrays,multiple queues and linked lists stored locally and/or remotely, presentsimilar tradeoffs.

[0099] Data management engine 165 returns stored data to authoringengine 160 in a manner essentially the reverse of that for storing data.Volume 1100, upon receipt of a request for stored data, parses therequest call for a data type, searches its contained objects list for acorresponding object, and forwards the request to title key jump source1101, first play jump source 1102, media database 1103, DVD layoutproperties list 1105, movies list 1106, menus list 1107 or connectionsets list 1107. Movies list 1105, menus list 1106 or connection setslist 1107, upon receipt of such a request, parses its available objectslist and forwards the message correspondingly to a movie object, menuobject or connection list object, and so on, until the message isreceived by a last recipient object. The last recipient object thenretrieves the requested data and sends the data in the reverse directionof request receipt until the data reaches volume 1100. Volume 1100, uponreceipt of the data, sends the requested data to authoring engine 160.(Error handling and messaging functionality are otherwise handled in aconventional manner.)

[0100] Data management engine 165 further responds to queries fromauthoring engine 160 for purposes such as totaling the number of dataelements of a given type or for reviewing the contents of a particularobject's data list. As with data storage and retrieval above, datamanagement engine 165 receives a call from authoring engine 160requesting information. Volume 1100 parses the message, polls itsavailable objects list and sends the message to a corresponding object.For objects linked to a tree-structure, such as movies list 1105, menuslist 1106 and connection sets list 1107, the message is forwarded downthrough respective objects as already discussed, and a last recipientobject will respond. If the message requests, for example, a totalnumber of data elements of a given type, then a last recipient willeither poll its totals variable or, if necessary, poll its data list forcorresponding data, count the number of corresponding occurrences andreturn a response including the total. The response is sent back throughthe tree structure to volume 1100, which sends the message (includingthe total) to authoring engine 160. Given the relatively small number ofobjects, alternatives (such as asynchronous multiple-messaging and, inparticular, broadcast messages) add some expediency, but withunnecessarily added complexity.

[0101] As with the authoring engine interface objects, the object types,inter-object messaging protocol and data objects utilized in datamanagement engine 165, in view of the disclosure herein, will beapparent to those skilled in the computer arts. Preferably, availableobject libraries from Microsoft® are utilized. For example, thepreferred available objects and data lists utilize Standard TemplateLibraries and, in particular, Expandable Indexed Buffered/VectoredLists. Such objects provide robust response with the flexibility ofexpandable lists and indexed vectors for easy lookup in light of thetypically small number of objects and datasets, among other factors. Asnoted earlier however, use of an object-oriented architecture and/or thespecific data structures are not essential and many conventionalalternatives can be utilized.

[0102] As discussed, the particular arrangement of objects of thepreferred data management engine 165 is preferred according to itsflexibility, performance and adaptability among other factors. It shouldbe noted therefore, that any number of modifications will be apparentaccording to the teachings and within the spirit and scope of theinvention.

[0103]FIGS. 12a through 15, with reference to FIGS. 2 and 11, illustratecompilation according to a preferred embodiment of the invention.

[0104] As shown generally in FIG. 12a, compiler 170 (FIG. 2) preferablyoperates on data entered through the authoring process into theinterface 160 a of authoring engine 160 (FIG. 2) and stored by datamanagement engine 165 in three stages. In step 1201, compiler 170 buildsan intermediate skeleton-form PGC layout data structure. Theskeleton-form PGC layout data structure is preferably formed accordingto DVD program code segment (“program chain” or “PGC”) abstractions anda network abstraction according to the invention, utilizing only summarydata gathered from data management engine 165. Broadly stated, each PGCabstraction is preferably comprised of pre-determined commandcombinations, wherein the number of PGCs of a given type and the numberof command combinations of a given type (e.g. button commandcombinations) are determined according to either a default value (e.g.typically one PGC) or according to the number of corresponding authoredelement types. (e.g. the number of menu buttons in a given menu).

[0105] In step 1203, compiler 170 resolves source-target connections asindices to source and target identifier information within datamanagement engine 165. In step 1205, compiler 170 replaces the indiceswith identifier information which is retrieved by further querying datamanagement engine 165.

[0106]FIG. 13 illustrates a preferred PGC layout structure according tothe invention. As shown, the PGC layout structure is divided into asingle first play PGC space 1301 (in accordance with the DVDSpecification), a single video manager (“VMGM”) domain 1302, and one ormore video title set (“VTS”) domains (e.g. 1303 and 1304) according tothe number of movies in the movie title.

[0107] The preferred VMGM domain PGC layout structure includes a singletitle key PGC abstraction, 1321 and a single movie router PGCabstraction 1322. Thereafter, the VMGM PGC structure includes 2 menu PGCabstractions (e.g. 1323 a and 1323 b) for each authored menu and asingle PGC abstraction for each end command (in each movie) that anauthor for which an author has specified a connection. As will bediscussed further, each menu PGC abstraction pair includes a menudisplay PGC (e.g. 1323 a and 1324 a) and a menu button router PGC (e.g.1323 b and 1324 b).

[0108] Each VTS domain PGC layout structure (e.g. 1303) includes a moviedisplay PGC 1331 and a video title set menu (“VTSM”) area 1332. VTSMarea further consists of from one to four remote key router PGCs (e.g.remote key router PGCs 1332), depending upon the number of differentremote key commands necessary, given the preferred layout structure, torealize the chapter target connections selected using connection view901. More specifically:

[0109] number of remote key router PGCs in a given VTSM=total number ofchapter points in a corresponding movie/25 (rounded, if a non-integer,to a next higher integer value).

[0110] In each case, an attempt has been made to minimize the number ofPGCs without detrimental impact on flexibility. Thus, while the numberof PGCs is as indicated above, complete authoring flexibility withregard to connecting menus, menu buttons and presentation data withoutconcern for limitations of the DVD programming specification 207 (FIG.2) is provided. Further, the practical impact of resultant limitationsis also minimized.

[0111] For example, the number of remote key router PGCs per VTSM areacalculation reflects that each chapter point abstraction requires morethan four commands. This in turn reflects that only one hundred twentyeight commands are allowable in a single PGC chain in accordance withthe DVD programming specification 207. While not essential, placing eachabstraction completely within a separated chains and in equal numbersthroughout like chains provides an efficiently symmetrical structure.Since DVD programming specifications 207 provide for up to ninety ninechapter points per movie, a maximum of four PGC abstractions is requiredwithout detrimental impact in terms of connectability. Considering thesame parameters and calculations for menus however, it is seen that onlytwenty five menu buttons are available per menu without limitation onconnectability. In practical terms however (i.e. displaying a menu on aconventional television set), this number does not present any practicaldetrimental effect.

[0112] The use of consecutive locations in the PGC layout structuregreatly simplifies the task of finding specific PGCs relating tospecific data types and further for resolving PGC connections. A movietitle PGC will always be the first element, a movie router PGC willalways be the second element, and a display menu PGC can always belocated merely by adding a known constant plus two times the menunumber, etc.

[0113] Those skilled in the art will appreciate however, in view of thediscussion herein, that the PGC abstractions provide for other thanconsecutively arranged elements as an indexed list in memory 120 (FIG.1). Such alternatives, for example, include but are not limited tomultiple lists, queues and/or multi-dimensional arrays stored in memory,in other media, and/or in more than one media either locally or in adistributed fashion, as with data management engine 165. Such methodscan be useful where more than one authoring location or otherdistributed environments are utilized.

[0114] The FIG. 12b flowchart, with reference to FIG. 13, shows ingreater detail how compiler 170 constructs a preferred PGC layout datastructure in an initial skeleton form. As shown, compiler 170 begins bystoring a first play PGC abstraction, a title key PGC abstraction and amenu router PGC abstraction into PGC layout structure 1300 (FIG. 13) insteps 1207, 1208 and 1209 respectively. Next, in step 1213, compiler 170queries data management engine 165 for a total number, MenusTot, ofmenus authored and, in step 1214, initializes a menu pointer, MenuPtr.In step 1215, compiler 170 queries data management engine 165 for atotal number, ButtonsTot, of buttons authored in a current menu (e.g.initially, a first menu). MenusTot will specify the number ofpre-determined menu display and menu button router PGC abstractions(i.e. “menu PGC abstraction pairs”) that compiler 170 will add to thestructure, while ButtonsTot will specify the number of commands thatcompiler 170 will add to each PGC of a current menu PGC abstractionpair.

[0115] In step 1216, compiler 170 adds a menu PGC abstraction pair toVMGM PGC structure 1302 (FIG. 13) corresponding to the existence of andthe number of buttons in a current authored menu (e.g. initially, afirst menu). If, in step 1217, one or more menus are not yet added toVMGM PGC structure 1301, then in step 1218, compiler 170 increments themenu counter and returns to step 1211.

[0116] At this point, compiler 170 lacks any authoring information otherthan MenusTot and a respective ButtonsTot value for each current menu. Asimilar same lack of further authoring details will also exist for otherPGCs in the skeleton-form, PGC layout structure. The preferred PGC andnetwork abstractions of the invention however, enable compiler 170 toaccommodate missing authoring details merely by inserting null values(“no-ops”) into the commands of the abstracted PGCs for unknownconnection information (i.e. source-target identification information).As discussed, compiler 170 will preferably resolve these no-ops later incompilation. These abstractions further enable menu PGCs to be createdindependently of movies and movie arrangements. Thus, independentlycreated/conceived menu PGCs provide extensive flexibility, allowing anauthor to link any available menu button of any menu to any potentialtarget using a user-friendly interface such as the preferred connectionview 901.

[0117] If instead, in step 1217, all authored menu layouts are reflectedby corresponding menu PGC abstraction pairs, then compiler 170 proceedsto step 1219. In step 1219, compiler 170 queries data management engine165 for the total number, MovieTot, of movies, which compiler 170 willuse to create end commands, VTSs and VTS contents. In step 1221,compiler 170 initializes a current movie pointer (“MoviePtr”), as wellas two counters, “EndTot” and “Remote”. Compiler 170 will use EndTot tocount the number of available end-of-chapter conditions in each moviefor which an author has specified connections and will use Remote tocount the number of available playback interruption conditions (i.e. bya user pressing a DVD-player control, typically on a remote controldevice) for which an author has specified connections.

[0118] In step 1223, compiler 170 queries data management engine 165 forthe total number of chapters (“ChapterTot”) in a current movie (e.g.initially, the first movie) and, in step 1225, initializes a currentchapter pointer (“ChapterPtr”). If, in step 1227, the author hasspecified a target for the current chapter, end-of-chapter condition(i.e. using connection view 901), then, in step 1229, compiler 170increments EndTot; otherwise, compiler 170 proceeds to step 1231.Similarly, if, in step 1231, the author has specified a target for thecurrent chapter, remote-control key playback interruption (“remote-key”)condition, then, in step 1233, compiler increments Remote; otherwise,compiler 170 proceeds to step 1235.

[0119] The existence of authored connections is determined similarly forboth end-of-chapter and remote-key conditions. Preferably, objects1101-1163 (FIG. 11) contain actual source and target identifierinformation (i.e. corresponding to authored sources and targets), whilethe connection objects (e.g. 1171 a) contain pointers to data stored bythese objects. Stated alternatively, as a new potential source isauthored, a connection object is instantiated, including a sourcepointer that points to the potential source and a null-value targetpointer; if an author later connects such a source, then thecorresponding connection-object target pointer value is replaced by apointer to the target object. (Subsequent editing by an authorcorrespondingly deletes or instantiates a connection object and/orchanges a source pointer or target pointer value.)

[0120] Therefore, compiler 170 determines the existence of a connectedend command by first querying each connection object for a sourcepointer pointing to the currently selected chapter-object. Once found,compiler 170 checks the corresponding target pointer. A null-valuetarget pointer indicates an unconnected end command while anon-null-value target pointer indicates the existence of a connection.Remote key (i.e. “menu key” in FIG. 11) connections are similarlydetermined by finding an identifier in a current chapter menu key object(e.g. 1157), finding the corresponding source pointer in one of theconnection objects, and then querying the connection object for theexistence of a corresponding non-null-value target pointer.

[0121] Those skilled in the art, in view of the foregoing, willappreciate that considerable variation of the above structure willprovide the same, related or similar functionality. For example,identifiers, labels and even complete movie tree, menu tree and/or otherobjects could well be contained within or duplicated within theconnections-tree (i.e. objects 1107-1173). A single connection objectcould also be used (i.e. having a single list of all connections), ascould connection objects that remain despite the deletion of a source.Other variations are also anticipated. The current structure is however,preferred in that it provides a compilation time of only a fewmilliseconds, minimizes memory usage and further facilitates debugging,emulation, simulation and overall symmetry by separating these objects(and their contained data). In simulation, for example, the restrictionsimposed by the DVD Specification are not controlling and simulation cantherefore more efficiently utilize authoring data directly from thepreferred, non-integrated data management engine 165 object structure.

[0122] Returning now to FIG. 12b, if, in step 1235, more chapters remainin the current movie, then compiler 170 increments ChapterPtr andreturns to step 1227; otherwise, compiler 170 proceeds to step 1237. Instep 1237, compiler 170 adds a 1-4 PGC, end command router PGCabstraction to layout structure 1300 (FIG. 13). In step 1238, compiler170 creates a VTS domain for the current movie (i.e. including a VTSM),adding to the VTS domain a movie display PGC in step 1239 and adding a1-4 PGC, remote key PGC abstraction in step 1240.

[0123] If, in step 1241, more movies remain in the current movie title(i.e. tested by comparing MovieTot with MoviePtr), then compilerincrements moviePtr in step 1243, re-initializes EndTot and Remote instep 1245 and returns to step 1223. Otherwise, formation of a PGC layoutstructure in skeleton form has been completed.

[0124] The FIG. 12c flowchart with reference to FIG. 11 shows howcompiler 170 replaces the no-ops in (skeleton form) PGC layout structure1300 with indices (i.e. source or target pointers) to respective sourcesand targets, and then further replaces the indices with elementidentifiers. In step 1251, compiler 170 initializes a movie pointer(“MoviePtr”) to a first movie, a chapter pointer (“ChapterPtr”) to afirst chapter, a menu pointer (“MenuPtr”) to a first menu and a buttonpointer (“ButtonPtr”) to a first button.

[0125] In step 1253, compiler 170 queries data management engine 165(i.e. connection-objects) for a source-pointer to a next (initially, afirst) author-connected button. As discussed earlier, the connectionobject checks its source-pointer for a corresponding source having acorresponding non-null-value target pointer. Since specific connectionvalues (rather than the existence of a connection as with FIG. 12b) arerequired in this case, the query utilized results in the return of sucha source-pointer. In step 1255, compiler 170 uses the returnedsource-pointer to query data management engine 165 for the correspondingtarget-pointer and, in step 1257, compiler 170 uses the returned indicesto query data management engine 165 (e.g. via volume 1100, menu-1 1160 aand button list 1161 to button-1 1162 a) for the source and targetidentifiers corresponding to the source and target pointers. Then, instep 1259, compiler 170 replaces the current button command no-ops (ofthe current menu PGC abstraction pair) with the returned identifiers.

[0126] If, in step 1261, more buttons remain unresolved in the currentmenu, then compiler 170 increments ButtonPtr in step 1263 and returns tostep 1253; otherwise, compiler 170 proceeds to step 1265. If, in step1265, menus remain unresolved, then compiler 170 increments MenuPtr andresets ButtonPtr to one in step 1267, and then returns to step 1253;otherwise, compiler 170 proceeds to step 1271.

[0127] Having resolved and replaced all menu button no-ops, compiler 170next resolves all chapter end-command and remote-key PGC abstractionno-ops in a similar manner. Compiler 170 queries data management engine165 for a (next connected) current chapter end command source-pointer instep 1271, uses the returned source-pointer to query data managementengine 165 for a corresponding target-pointer in step 1272, uses thepointers to query data management engine 165 for correspondingidentifiers in step 1273 and replaces corresponding layout structure1300 PGC commands with the returned identifiers in step 1274. Similarly,compiler 170 queries data management engine 165 for a (next connected)current remote key source-pointer in step 1277, uses the returnedsource-pointer to query data management engine 165 for a correspondingtarget-pointer in step 1278, uses the pointers to query data managementengine 165 for corresponding identifiers in step 1279 and replacescorresponding layout structure 1300 PGC commands with the returnedidentifiers in step 1280.

[0128] If, in step 1283, more chapters remain unresolved, then compiler170 increments the chapter pointer in step 1285 and returns to step1271. If instead, no chapters remain unresolved in the current movie,then compiler 170 proceeds to step 1286. In step 1286, compiler 170queries data management engine 165 (i.e. via volume 1100 to mediadatabase 1103 of FIG. 11) for all audio and video file references whichreference the current movie. In step 1287, compiler 170 invokesmultiplexer 185, which retrieves the referenced audio and video filesand outputs a resultant multiplexed data file in a conventional mannerand in accordance with the DVD disk format specifications 205 (FIG. 2)of the DVD Specification.

[0129] If, in step 1288 more movies remain unresolved in layoutstructure 1300, then compiler 170 resets pointers for the next movie andfirst chapter in step 1289 and returns to step 1271. Otherwise, compiler170 (in a similar manner) resolves first play, title key jump source andmenu router no-ops respectively in steps 1291, 1293 and 1295. Then, instep 1297, compiler 170 saves the PGC layout structure as a stored file.

[0130] With regard to FIGS. 12b and 12 c, total authored element values(i.e. such as MenusTot and ButtonsTot) are maintained on an ongoingbasis in a corresponding list object or the functional equivalent of alist object as already discussed. For example, movies-list object 1105(FIG. 11), in addition to a list for containing references to allinstantiated movie objects, also contains a variable for updating thetotal number of movies in a current movie title during the course of oneor more authoring sessions. Similarly, button-list object 1161 containsa list of instantiated button objects (e.g. 1162 a through 1162 b) aswell as a variable indicating the total number of buttons in menu-1.Other list objects similarly include ongoing totals which are updatedduring the course of authoring. One reason is that some early-generationDVD-players limit the available memory space for storing PGCs, whichcorrespondingly limits the number of elements (e.g. menus, menu buttonsand chapters) that the invention permits to be authored. These limitsand/or current totals are therefore selectively conveyed to an authorthrough interface 160 a. Ongoing totals are also beneficial in that notime periods are required during compilation for calculating suchtotals.

[0131] As will be understood by those skilled in the art however, totalvalues might become unimportant for other than compilation purposes asDVD-players are manufactured with increasing resources in conformancewith the current DVD Specification, in accordance with expanded DVDcapabilities and in accordance with the requirements of non-DVD systems.In such cases, totals can alternatively be calculated duringcompilation.

[0132] The use of preferably pre-determined PGC abstraction typescomprising preferably pre-determined command combinations and thepreferred PGC layout structure are thus factors in providing a maximizedauthoring flexibility and efficient compilation among other benefits.Available connections remain completely flexible during authoring and,in fact, until substitutions are made for no-ops during compilation. Thepreferred structures of PGC abstractions further add to compilationefficiency, since a skeleton can be formed with only summary authoringdata, and then authoring details can be quickly added thereafter.

[0133]FIGS. 14 and 15, with reference to FIG. 13, illustrate a preferrednetwork or “connection-switching” abstraction according to theinvention. The connection-switching abstraction, while operationallyactive only during playback of a movie-title, is also a factor indetermining PGC abstractions produced by compiler 170 as well as themovie, menu and connection movie-title abstraction utilized by datamanagement engine 165, interface 160 a and authoring engine 160 (FIG.2).

[0134] Details of the DVD Specification including but not limited tomultiplexed data stream and DVD player configurations, data formats,protocols and loading of data are known to those skilled in the art andwill therefore be discussed only to the extent required for anunderstanding of the invention.

[0135] DVD programming specifications 207 (FIG. 2) provide that PGCs canreside (along with the corresponding presentation data) in virtualstructures including a first play space, a video manager (“VMGM”) andany of 99 video title sets (“VTSs”), each of which includes a videotitle set menu space (“VTSM”). Among the limitations of this virtualstructure however, is first that a PGC in an initial VTS or VTSM cannotdirectly trigger (i.e. jump to, using a DVD jump command) a PGC storedin another VTS (or VTSM). For example, while a PGC in an initial VTS can“playback a chapter of presentation data” and the conclusion of chapterplayback can trigger a “followup” PGC, the followup PGC cannot be storedin a different VTS. Similarly, an initial PGC used to respond to DVDconsumer menu-button activation cannot trigger a second PGC which isstored in a different VTS. A further relevant limitation is that theformat of performance data must remain constant within a given VTS. So,for example, a video data stream having one aspect ratio cannot bestored in the same VTS with another video data stream having a differentaspect ratio.

[0136] The FIG. 14 functional diagram illustrates how the preferredconnection-switching abstraction provides a flexible and robustfunctional superstructure within which movie-title, DVD-player andinteractively occurring consumer-control events are routed and executed.In the figure, VTS-A 1303 and VTS-A+1 exemplify any two different VTSswhich have been created during compilation of a movie-title. It shouldalso be noted that the illustrated connection arrows only denote the“path” from one box (i.e. PGC abstraction, PGC or command-set) toanother that can result from an author's use of connection view 901(FIG. 9). Thus, fewer connections than those illustrated might beauthored and each path from one box to another is accomplishedindividually using a single “jump command” or a single transfer ofcontrol by a DVD-player. (The use of multiple connected arrows andshared arrows is used only for clarity sake, since the alternative useof individual arrows between each pair of boxes might otherwise obscurethe invention.)

[0137] Within each VTS, only a movie display PGC abstraction operates asa “control PGC” (i.e. directly controls menu and/or movie display). Forexample, VTS-A 1303 includes movie display PGC abstraction 1331 and(within its VTSM domain 1322) remote key PGC abstraction 1322 a. Moviedisplay PGC abstraction 1331 comprises a single PGC which includes acommand-set (“pre-command”) for selecting a chapter and initiatingplayback of the chapter, as well as an end command “cell command” thatinitiates routing upon the occurrence of an end-of-chapter-playbackcondition. Remote menu key 1431 a, which denotes an automatic DVD playerfunction, traps and forwards a remote-key condition (i.e. userdepression of a remote menu key which interrupts playback). Remote menukey router PGC abstraction 1322 a of VTSM-A 1322 sets the authoredtarget for a corresponding remote menu key condition (i.e. where aconsumer presses a remote menu key during playback) and then routescontrol to a corresponding movie PGC abstraction or menu PGC abstractionwithin VMGM 1302. Other VTSs (e.g. VTS-A+1 1304) are similarlystructured for each movie within the current DVD movie-title.

[0138] Each remote menu key router PGC abstraction includes up to 4 PGCsto accommodate the up to 99 chapter points per movie limitation of theDVD Specification. The first remote menu key PGC is always assigned as aroot menu and is always a hardwired (i.e. unalterable) target for anyremote menu key condition (in accordance with the DVD Specification).Therefore, in order to provide for chapter dependent routing of a remotemenu key condition, a DVD-player system register must first be queriedfor the last played chapter. Using the returned last played chapterinformation, program execution is then diverted to the correspondingauthored remote menu key router PGC.

[0139] VTSM 1302 comprises the discussed menu display PGC (e.g. 1322)and menu button router PGC (e.g. 1323 b) abstraction pairs (forproviding menu control), as well as the remaining router PGCabstractions. More specifically, movie router PGC abstraction 1322 actsas a playback bridge between VTS domains, receiving control from aremote key PGC in a first VTS (e.g. remote key PGC 1322 a of VTS 1303)and then forwarding control to a movie display PGC abstraction in secondVTS (e.g. movie play PGC 1341 of VTS 1304). In contrast, end router PGCabstractions (e.g. 1325 and 1326) can be author-connected to routecontrol from an end-of-chapter condition to either a selected chapter ina selected movie, or to a selected menu button in a selected menu.

[0140] As shown, a separate PGC is provided for each author-connectedend-of-chapter condition. Each end command router PGC abstraction ispaired with (i.e. responds to) a specific end command such that eachend-of-chapter condition for a given movie will be routed from the endcommand to a unique end router PGC abstraction. Separate end commandPGCs are required due to a flaw in current generation DVD-playerswhereby the last played chapter is not reliably available at the end ofchapter playback. Upon correction of this flaw in future generationDVD-players however, end command routing can be accomplished in a mannerconsistent with remote menu key PGC abstractions (i.e. using only up tofour end-command router PGCs per movie).

[0141] A menu display PGC abstraction (e.g. 1323 a), when it receivescontrol as a target and thereafter while a consumer continues to depressmenu navigation buttons, effectuates control by highlighting a menubutton and displaying the menu. If however, a consumer activates a menubutton, then the DVD-player initiates the corresponding router PGCabstraction (e.g. 1323 b), which routes control (i.e. according to anauthored connection) to either a movie display PGC or to a menu displayPGC.

[0142] For clarity sake, the first play PGC abstraction 1301 and titlekey PGC abstraction 1321 (FIG. 13) are not shown in FIG. 14. Eachoperates to transfer control to either a menu display PGC or a moviedisplay PGC as with the end command router PGCs and menu router PGCs.First play PGC 1301 is stored in a separate DVD-player storage location,while title key PGC 1321 is stored in VMGM 1302.

[0143] While those skilled in the art will appreciate, in view of thediscussion herein, that considerable variation might be utilized,iterative experimentation with different connection-switchingabstractions and DVD players has revealed a number of considerations.For example, command execution delays will necessarily occur as a resultof PGC execution and greater delays typically result from transfer ofcontrol between a VTS (e.g. 1303 and 1304) and VMGM 1302. Anotherexample is that a delay occurring prior to the start of a movie isobserved to be more acceptable than a similar delay during navigationthrough what can be a large number of menus. A still further example isthat consistent delay periods for similar transitions is more acceptablethan inconsistent delays for similar transitions.

[0144] Thus, the preferred connection-switching abstraction provides agenerally symmetrical structure wherein delays are first minimized bysource-router-target execution paths having a minimum number of PGCs andPGC commands. Movie display PGC abstractions are further placedsimilarly within each VTS, while menu PGC abstraction pairs are placedsimilarly within VMGM 1302. (Note that an author typically only connectsthe end command of a last chapter within any given movie, such that theDVD-player will continuously play all chapters with the movie beforecontrol is routed outside the corresponding VTS). In addition, movierouter 1322 is only used for VTS-to-VTS transitions This reflects, forexample, that inconsistent delay between movie-to-movie playback andmenu-to-movie playback is more acceptable than imposing further delay onmenu-to-movie playback or other alternatives. (For example, furtherdistribution and/or re-distribution of movie and/or menu routingfunctions have been observed to produce subjectively less acceptableresults.) In addition, movie router 1322 complexity and PGC length istherefore reduced. It should be understood however, that these alreadyshort delay periods will further decrease as advances are made inDVD-player technology and that the resulting decreasing importance ofsuch considerations might well contribute to furtherconnection-switching abstraction variations.

[0145] The FIG. 15 flowchart broadly illustrates the operation ofpreferred connection-switching abstraction 1400. In step 1503, firstplay PGC abstraction is invoked in response to insertion of amovie-title into a DVD-player. The first play PGC abstraction (i.e. nowthe current PGC abstraction) determines target information (i.e. atarget identifier and, if needed, target parameters). If, in step 1505,a router is required, then, the current PGC abstraction routes thetarget information and control to a next router abstraction in step 1507and operation returns to step 1511. If no router is required in step1505, then, in step 1509, the current PGC abstraction routes the targetinformation to the target PGC abstraction.

[0146] If, in step 1511, the target is not a chapter (i.e. playback of achapter is not the resultant authored event) then the target displays amenu (i.e. according to the target information) in step 1513 and theDVD-player waits for a menu button to be selected (i.e. step 1513through 1515 act as a wait loop). If, in step 1515 a menu button isselected, then the current PGC abstraction sets authored targetinformation for the selected button in step 1517 and operation returnsto step 1505.

[0147] If instead, in step 1511, the target is a chapter, then thetarget initiates playback of the chapter. If further, in step 1525, aconsumer invokes the remote menu key during playback of the chapter,then the current PGC abstraction sets authored target information instep 1527 and operation returns to step 1505. If, in step 1525, theremote menu key is not invoked (i.e. the chapter plays uninterrupted toits conclusion) and a chapter end command target has been authored, thenthe current PGC abstraction sets the authored target information in step1537 and operation returns to step 1505. If, in step 1535, a chapter endcommand target has not been authored, then operation continues in step1545.

[0148] If, in step 1545, more chapters exist in the current movie, thenthe DVD player increments the chapter number in step 1543 and operationreturns to step 1523. If instead, in step 1545, no more chapters remainunplayed in the current movie, then the player suspends playback and (insome models) switches itself off.

[0149] For clarity sake, the operation of preferred connection-switchingabstraction 1400 will also be discussed, by way of example, withreference to FIG. 14. If, for example, an authored-connection for firstplay is set to begin playback of a first chapter of a first movie storedin VTS-A 1303, then upon insertion of the DVD movie-title into aDVD-player, movie display PGC abstraction 1331 will be invoked. Moviedisplay PGC 1331 will select and initiate playback of the first chapter.

[0150] If the first chapter playback is interrupted by a remote menu keycondition, then 1 o the DVD-player will automatically trap the condition(i.e. box 143 la) and will initiate the root menu PGC of remote menu keyrouter 1322 a of VTSM-A 1322. Assuming further that less than 25chapters exist in the first movie, the root menu PGC of remote menu keyrouter 1322 a (i.e. now the current source PGC abstraction) will set theauthor-selected target for the first chapter remote menu key conditionand will route control to either movie router 1322 or a menu display PGC(e.g. 1323 or 1324) within VMGM 1302. If movie router 1322 receivescontrol, then upon receipt, movie router further routes control to theauthor-connected movie display PGC, in this case, movie display PGC 1341of VTS-A+1 1304, which will set and initiates playback of theauthor-selected chapter of the VTS-A+1 movie.

[0151] If instead, playback of the first movie is not interrupted andonly the last chapter of the first movie includes an author-connectedend command, then the DVD-player will continue to play successivechapters of the first movie until the conclusion of the last movie. Atthe conclusion of the last movie, the DVD-player will execute cellcommand 1431 b (i.e. end command), which will transfer control to thePGC in end router 1325 (in VTSM 1302) that corresponds with the chapterlast chapter played, i.e. the last chapter of VTS-A movie. (Since, inthis case, only one chapter in the VTS-A movie has a connectedend-of-chapter playback condition, end router 1325 will include only theone corresponding PGC.)

[0152] Upon receipt of control from end command 1431, end router 1325(i.e. now the current source) will set the correspondingauthor-connected target included in end router 1325. Assuming the targetis the VTS-A+1 movie, end router 1325 will further route control tomovie display PGC 1341 of VTS-A+1 1304, which will set and initiateplayback according to the chapter of the VTS-A+1 movie set by end router1325. (Since control is not being routed from one VTS to another VTS,movie router 1322 is not utilized.)

[0153] If instead, the current source PGC of end router 1325 (i.e.again, the only PGC in end router 1325 in this example) includes anauthor-selected connection to menu N 1323, then end router 1325 will settarget parameters and will route control to menu display PGC 1323 a.Menu display PGC 1323 a will highlight the button of menu-N 1323according to the received target parameters and will then display menu-N1323. Menu display PGC 1323 a will thereafter continue to be invoked bythe DVD-player and will continue to highlight a button and displaymenu-N 1323 correspondingly with each successive uninterrupted (i.e. byconsumer selection of a conflicting DVD control function) consumerdepression of a navigation button. If however, the consumer nextactivates a displayed menu button, then the DVD-player will invoke menubutton router PGC 1323 b. Once invoked, menu button router PGC 1323 bwill set target parameters according to the author-selected connectionfor the activated button, and so on.

[0154] Attachment A attached hereto provides computer listings ofpreferred PGC abstractions source code according to the invention. Forclarity sake, compilation has already been completed. Statedalternatively, the no-ops initially included in the skeleton-form PGClayout structure have been replaced by indices and the indices have beenresolved to source and target identifiers using the discussed compilerand compilation methods.

[0155] As shown in attachment A, the preferred PGC abstractions utilizea number of DVD player registers. According to the DVD specification,each DVD player includes 16 general purpose registers (“GPs”), and 20system registers (“SPs”). The GPs are functionally undefined and merely“available for use” by movie title control program PGCs. Conversely, theSPs have fully defined purposes consistent with DVD player operation andmovie title control program interfacing.

[0156] The preferred GPs utilization and corresponding namingconventions according to the invention are indicated in the followingchart. As shown, PGC abstractions exclusively utilize only 5 GPs,leaving a maximized number of remaining GPs available for adding furthercapabilities. Register Referenced as Description GP10 Stream Select Bit15 = Select audio stream on/off Bit 14 = Select subtitle stream on/offBit 13 = Select angle stream on, off Bits 10-12 = Audio stream numberBits 7-9 = Angle stream number Bits 0-6 = Subtitle stream number GP12Target Movie Number Stored number = Movie number GP13 Target ButtonNumber Stored number = Button number GP14 Target Chapter Number Storednumber = Chapter number GP15 Temporary Register Stored number = valueused with current PGC SP7 Last Chapter Played DVD player fills theregister with the number of the last chapter played SP8 Last HighlightedButton DVD player fills the register with the number of the lasthighlighted button

[0157] As illustrated by the register utilization chart, GPs areutilized by source PGC abstractions primarily for designating (i.e.resolving an available connection to) target PGC abstractions and forpassing to the targets parameters affecting target operation. The GPsare further utilized by target PGC abstractions primarily forestablishing, manipulating and recalling localized variables (i.e.relating to a currently executing PGC command set).

[0158] For example, at a time prior to initiating playback of a chapter,a source PGC abstraction stores a value in GP10 (“stream select”). Thatvalue will later indicate to a target PGC which audio, subtitle and/orangle stream is to be selected for movie playback. A further example isthat, at a time prior to routing control to a target PGC abstraction, asource PGC abstraction stores a target's designation in a combination ofregisters GP12 (“Movie Number”) and GP14 (“Chapter Number”) for a movietarget or GP13 (“Button Number”) for a menu target. Finally, PGCabstractions preferably utilize GP15 to temporarily store values,typically for use within a current PGC operation.

[0159] In most cases, only a portion of a given register (“registerbits”) are utilized, while conversely, a given register may be used formultiple purposes, as seen in the utilization of GP10 in the registerchart. Those skilled in the art will appreciate, given the discussionherein, that the preferred embodiment enables certain advantages. Amongthese are that a single register or register set can be designated inall cases for similar purposes, thereby minimizing complexities, thenumber of registers required and the number of commands required withina PGC without detrimentally affecting routing or parameter passingflexibility. Similarly, operations required to parse register datacontaining multiple data values are not needed. Other arrangementsconsistent with the teachings of the invention however, are likely inview of other applications facilitated by these teachings and inaccordance with the scope and spirit of the invention.

[0160] While the present invention has been described herein withreference to a particular embodiment thereof, a latitude ofmodification, various changes and substitutions are intended in theforegoing disclosure, and it will be appreciated that in some instancessome features of the invention will be employed without a correspondinguse of other features without departing from the spirit and scope of theinvention as set forth.

We claim:
 1. A method of making a multimedia program comprising thesteps of: selecting an arrangement of performance information containinga plurality performance elements; creating a layout of a performanceinformation access structure containing a plurality of access elements;linking the performance elements and access elements with linkinginformation to create linked performance and access elements; andautomatically generating programming data from the linked performanceand access elements to construct said multimedia program.
 2. A systemfor making a multimedia program comprising: means for selecting anarrangement of performance information containing a pluralityperformance elements; means for creating a layout of a performanceinformation access structure containing a plurality of access elements;means for linking the performance elements and access elements withlinking information to create linked performance and access elements;and means for automatically generating programming data from the linkedperformance and access elements to construct said multimedia program.